If you want to have a new type of paraphernalia to protect from wounds, however, that would all right. However, I propose that this paraphernalia be called "bodyguards" rather than "armour".
We already have those--they're called soldiers. I'm almost positive that unit size affects the chance of the infiltrator getting caught on his way to/from the tent.
I like the armor idea, I know there are plenty of people with older characters (such as myself) who HATE the 10+ days it takes them to heal. I would definitely love to give some of my characters extra protection.
